Why can't I continue typing after pressing spacebar?

[AC Question]

HTC One M7 phone - when replying to Hotmail message, after first word I press spacebar and window does not accept any further input. Behaviour only on my Hotmail account, not with gmail, what's app, text messages. I am using the swifty keyboard and have restarted phone, changed variations of settings on keyboard. unable to revert back to HTC sense tho as I have said, behaviour only on Hotmail account on phone. Any advice for fix grateful and appreciated. Cynthia